Complementary contours

The 2018 Outstanding Shotcrete Project Awards program shows the potential for spraying and layering fine aggregate, fast hardening, cement-rich mixes as an alternative or companion to conventional cast-in-place or precast concrete. The American Shotcrete Association (ASA) honors projects in Infrastructure, International, Pool & Recreational, Repair & Rehabilitation, Underground, and Architecture | New Construction categories.

effen Theater project principals: Superior Gunite, shotcrete contractor; Matt Construction, general contractor; Cemex, mix supplier; Renzo Piano Building Workshop/M. Arthur Gensler Jr. & Associates, architect/engineer; Academy Museum Foundation, owner.

Northeast Community Skate Park project principals: SPA Skateparks, shotcrete contractor; Core Construction, general contractor; Redi-Mix Concrete, mix supplier; New Line Skateparks, architect/engineer; City of Frisco, Texas, owner.

Brattleboro Bridge project principals: Superior Gunite, shotcrete contractor; PCL, general contractor; Carroll Concrete Co., mix supplier; Sebago Technics, architect/engineer; Vermont Agency of Transportation, owner.

The AMMP Geffen Theater in Los Angeles took the latter. Superior Gunite placed 7,000-plus yd. of shotcrete mixes for a new basement; seismic retrofit of the existing May Company Building; and, an elevated theater structure. Dubbed “The Bowl,” the theater combines precast concrete exterior panels with interior structural concrete requiring 2-ft. thick shotcrete placement of 50-ft. high, complex curved shear walls.

The Northeast Community Skate Park in Frisco, Texas, led the Pool & Recreational category. The 47,000-sq.-ft., destination-sized facility used 850 yd. of wet mix shotcrete, which contractor SPA Skateparks worked to Class A steel trowel finishes. Accounting for almost 50 percent of an 1,800-yd. concrete schedule, the sprayed material proved a natural choice because it is the most controlled and productive method to maintain tight tolerances while executing intricate shapes and contours—banks, quarter pipes, skateable art and various transitional elements among them.

The Interstate 91 Brattleboro Bridge in Vermont received honorable mention. While precast, sculpted rock form panels run up the piers, project principals noted the challenge of arched and inverted sections toward the girders. Shotcrete was used as a companion to the architectural precast, with contractor Superior Gunite carving freshly placed layers to match the panels.

Winning and honorable mention projects were announced at the ASA Shotcrete Convention & Technology Conference in Florida. “[They] exemplify how shotcrete placement creates high quality, durable concrete construction in a wide variety of applications. The projects demonstrate the inherent benefits of shotcrete, including enhanced sustainability, creativity, efficiency, strength and flexibility,” says ASA Executive Director Charles Hanskat. The association is accepting 2019 Outstanding Shotcrete Project Awards program entries through October, he adds. American Shotcrete Association, Farmington Hills, Mich., 248/848-3780;